Hydraulic-pressure-reducing valve



(No Model.) I

W. H. WOOD. HYDRAULIC PRESSURE REDUCING VALVE. N0. 512,142.

Patented Jan. 2, 18.94.

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ATTORNEYS- wAsummoN D s WITNESSES i UNITED STATES PATENT OFFICE.

YVILLIAM H. WOOD, OF MEDIA, PENNSYLVANIA.

HYDRAULIC-PRESSUR E-REDUCING VALVE.

SPECIFICATION forming part of Letters Patent No. 512,142, dated January2, 1894. Application filed January 9, 1893. Selial No. 457,849. (Nomodel.)

To aZZ whom it may concern:

Be it known that 1, WILLIAM H. WOOD, a subgect of the Queen of GreatBritain, and a resident of Media, in the county of Delaware and State ofPennsylvania, have invented certain new and useful Improvements in H3-draulic-Pressure-Reducing Valves; and I do hereby declare that thefollowing is a full, clear, and exact description of the invention, whch will enable others skilled in the art to which it appertains to makeand use the same, reference being had to the accompanymg drawings, whichform a part of this specification, and in which- Flgure 1 is a sideelevation, in outline, of a hydraul c riveting machine, illustrating theapplication of mypressrire-reducing valve. F g. 2 1s a side elevation ofthe valve; and Fig. 3 ma vertical sectional view of the same.

' Llke letters of reference denote corresponding parts in all thefigures.

Referring to the said drawings, the reference letter A denotes thecasing of a stationary hydraulic riveting machine, which, in this case,has a solid head or end a, and is mounted upon the rigid support or baseB, opposite to the fixed anvil-post or hob G, as usual in this style ofriveters. J

D 1s the pipe connecting the pressure-reduclng or regulating valve E tothe working cyl nder (shown in dotted lines) within the caslng. I

F is a pipe connection leading to the exhaust pipe G fro m thevalve-chamber b,which connects on the inside with the exhaust port 1nthe cylinder, and H is the pressure pipe leadlng from the accumulatorand through which water under a constantand even pressure e. the maximumpressure which obgalns 1n the accumulator) is fed into the cylin- Thepipe D, leading from the rear end of the working cylinder, back of itsplunger, is. threaded at its outer end and screwed into the threadedinlet cl of a casing M, the other end of which, forming the outlet fromsaid casing, is also threaded as shown at f to receive the upper end orelbow of pipe F, which connects the valve E with the exhaust pipe G. Thecasing M, has an interior chamber 6, 1n the top of which is an aperture,the upper end ofv which is ground to form a circular seat z' withbeveled edges for the valve I, the rim of which is also made sloping orbeveled to fit its seat so as to form a water-tight joint when the valveis down or closed. v

J is the valve-stem, which works through a central bore in a cap K, thereduced lower end 70 of which is screw-threaded and screwed into athreaded aperture in the neck m of easing M. a female thread, into whichis screwed the lower end of a cylindrical box or casing N, upon theupper end of which is screwed the top cap or cover S, which is providedwith a central screw-threaded aperture for the threaded stem or spindleQ, which has a smallhand-wheel g at its upper outer end. In

The upper end of this cap K has.

order to lock or fasten this screw-threaded spindle relative to casing Nand its cap or cover S, I provide the latter with a lock-nut T, bytightening down which the spindle may be firmly maintained in itsposition after proper adjustment. The upper end of the valve-stem J,where this projects into cylinder N, is reduced in diameter, as shownatj so as to form an annular shoulder or seat for a Washer O, whichforms the lower abutment or bearing for a coiled spring P, the upper endof which encircles a projection R at the lower or inner end of thescrew-spindle Q, taking against an annular flange or disk, 0" on saidspindle above its extension R. It will thus be seen that the spring P,operates to press valve I down upon its seat i so as to closecommunication between chamber 6 and the outlet f,- and further, that thespringpressure on the valve may be regulated by adjusting the spindle Q,by the screwing down of which the pressure is increased, while,reversely, the pressure is reduced by turning wheel q in the oppositedirection and screwing the spindle up.

From the foregoing description, taken inconnection with the drawings theoperation of this device will readily be understood. Assuming that themachine is to be used to its full capacity, 1. 6., with a maximumpressure for riveting thick plates, the spindle Q is screwed down so asto seat the valve with a pressure a little in excess of the maximumpressure of the accumulator, and it follows too that no water will passout through chamber 6 and valve 1' I into pipe F and the exhaust G; themachine exhausting in the regular manner. But when the riveter is to beworked at less pressure, for riveting thinner plates or analogous workof a lighter character, the pressure within the working cylinder may beproportionately reduced by adjusting the spindle Q so as to relieve thevalve from a certain amount of spring-pressure, corresponding to orcommensurate with the extent to which the cylinder is to be relieved.For example: if it is desired to work the machine at a pressure, we willsay, of only fifty tons (the accumulatorregistering its maximum ofseventy-five tons), then all that is necessary to do is to loosen thelock-nut T, screw up the spindle and thus relieve the spring until itspressure against valve I is equal to or counterbalances a pressure offifty tons on the area of the plunger within the working cylinder of themachine, and then again tighten down the lock-nut so as to maintain thespindle and valve in this adjusted position. It follows that there willnow be a constant outflow of water under pressureof twenty-five tons(viz: the excess of pressure, 1'. e. the difference of pressure betweenthe accumulator and the working pressure in the cylinder) through thevalvevl I and pipe F into the exhaust. Should it be desired to stillfurther reduce the working pressure, nut T is again loosened and thespindle is raised a little more, relieving spring-pressure on the valvecommensurate with the reduction of working pressure within the cylinder,for example,'from fifty to thirty tons, after which the nut is againfastened down as before. The outflow of water through thepressure-reducing valve will now be increased, due to the added excessof twenty tons pressure, .to which extent the working pressure on theplunger has been relieved, and there will be, as long as the machine isoperated with a hydraulic pressure of thirty tons, a constant outflow ofwater from the cylinder into the exhaust ata pressure of forty-fivetons, 2'. e., the difference between the working pressure and thepressure on the water in the accumulator. By testing the spring P anddevising a scale based on such tests and marked off, for example, on thestem of spindle Q, indicating the amount of relaxation required in thespring in order to effect a given reduction of pressure, thepressure-reducing device may be operated with certainty and accuracy sothat the workin g-pressure of the machine may be regulated at will andinstantly withoutinterfering with the accumulator or thehydraulic'connections of the machine.

It will be obvious that the detailed construction of thepressure-reducing device may be varied without affecting my method ofreducing the working pressure, and I desire it to be understood,therefore, that; I do not con fine myself to any specific constructionof this device per 86, although the apparatus herein described will befound inexpensive,

easy in its application and manipulation, and entirely satisfactory inits operation, 7 y

Having thus described my inventiom l claim and desire to secure byLetters Patent of the United States'-. g p p In 'a hydraulicriveting-machine of the character described, the combination of thefollowing elements,viz: the working-cylinder, the valve-chamber b, theinlet-pipe H, exhaust-pipe G, connecting-pipeD, pressure-re ducing valveE having inlet d and outlet f, and discharge-pipe F leadingfro'rn theoutlet f to the exhaust G below the valve-chamber; substantially as andfor the purpose shown and set forth. v p v In testimony that I claim theforegoing as my own I have hereunto affixed my signature in presence oftwo witnesses.

WILLlAM 11. wool).

Witnesses:

AUGUST PETERSON; BENNETT S. JONES.

